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* [PATCH v3 1/4] mtd: rawnand: gpmi: Refactor bch geometry settings function
@ 2022-04-04 19:54 Han Xu
  2022-04-04 19:54 ` [PATCH v3 2/4] mtd: rawnand: gpmi: Add strict ecc strength check Han Xu
                   ` (3 more replies)
  0 siblings, 4 replies; 9+ messages in thread
From: Han Xu @ 2022-04-04 19:54 UTC (permalink / raw)
  To: sean, frieder.schrempf, festevam
  Cc: ye.li, peng.fan, han.xu, miquel.raynal, linux-mtd

The code change refactor the bch geometry setting function, which still
use the legacy bch setting as default option, while user may choose to
use chips required minimum ecc strength by DT flag "fsl,use-minimum-ecc".

The driver uses legacy bch geometry settings by default, if the NAND
chips oob size is less than 1KB. The legacy_set_geometry() sets the data
chunk size(step_size) larger than oob size to make sure BBM locates in
data chunk, then set the maximum ecc strength oob can hold. It always use
unbalanced ECC layout, which ecc0 will cover both meta and data0 chunk.

For all other cases,set the bch geometry by chip required strength and
step size, which uses the minimum ecc strength chip required. It can be
explicitly enabled by DT flag "fsl,use-minimum-ecc", but need to be
en/disabled in both u-boot and kernel at the same time.

Signed-off-by: Han Xu <han.xu@nxp.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>

---
Changes since v2
 - split the ecc check to a single patch

Changes since v1
 - split the patch to two parts
 - change the commit log
 - add test tag
---
---
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 32 ++++++++++++++--------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index d96899fa90b7..4144d5937103 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -514,24 +514,32 @@ static int legacy_set_geometry(struct gpmi_nand_data *this)
 static int common_nfc_set_geometry(struct gpmi_nand_data *this)
 {
 	struct nand_chip *chip = &this->nand;
+	struct mtd_info *mtd = nand_to_mtd(&this->nand);
 	const struct nand_ecc_props *requirements =
 		nanddev_get_ecc_requirements(&chip->base);
+	bool use_minimun_ecc;
+	int err;
 
-	if (chip->ecc.strength > 0 && chip->ecc.size > 0)
-		return set_geometry_by_ecc_info(this, chip->ecc.strength,
-						chip->ecc.size);
-
-	if ((of_property_read_bool(this->dev->of_node, "fsl,use-minimum-ecc"))
-				|| legacy_set_geometry(this)) {
-		if (!(requirements->strength > 0 && requirements->step_size > 0))
-			return -EINVAL;
+	use_minimun_ecc = of_property_read_bool(this->dev->of_node,
+						"fsl,use-minimum-ecc");
 
-		return set_geometry_by_ecc_info(this,
-						requirements->strength,
-						requirements->step_size);
+	/* use legacy bch geometry settings by default*/
+	if ((!use_minimun_ecc && mtd->oobsize < 1024) ||
+	    !(requirements->strength > 0 && requirements->step_size > 0)) {
+		dev_dbg(this->dev, "use legacy bch geometry\n");
+		err = legacy_set_geometry(this);
+		if (!err)
+			return 0;
 	}
 
-	return 0;
+	/* otherwise use the minimum ecc nand chip required */
+	dev_dbg(this->dev, "use minimum ecc bch geometry\n");
+	err = set_geometry_by_ecc_info(this, requirements->strength,
+					requirements->step_size);
+	if (err)
+		dev_err(this->dev, "none of the bch geometry setting works\n");
+
+	return err;
 }
 
 /* Configures the geometry for BCH.  */
-- 
2.17.1


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 2/4] mtd: rawnand: gpmi: Add strict ecc strength check
  2022-04-04 19:54 [PATCH v3 1/4] mtd: rawnand: gpmi: Refactor bch geometry settings function Han Xu
@ 2022-04-04 19:54 ` Han Xu
  2022-04-05  7:28   ` Miquel Raynal
  2022-04-04 19:54 ` [PATCH v3 3/4] mtd: rawnand: gpmi: Rename the variable ecc_chunk_size Han Xu
                   ` (2 subsequent siblings)
  3 siblings, 1 reply; 9+ messages in thread
From: Han Xu @ 2022-04-04 19:54 UTC (permalink / raw)
  To: sean, frieder.schrempf, festevam
  Cc: ye.li, peng.fan, han.xu, miquel.raynal, linux-mtd

Add strict ecc strength check in gpmi_check_ecc() function, which is
same as nand_ecc_is_strong_enough() did. It will check both correct bits
and correct bits per byte to ensure it meets chip required ecc strength.

Signed-off-by: Han Xu <han.xu@nxp.com>

---
Changes since v2:
 - split the ecc check to a single patch
---
---
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 24 ++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index 4144d5937103..9a37f8cc663e 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -238,9 +238,14 @@ static void gpmi_dump_info(struct gpmi_nand_data *this)
 		geo->block_mark_bit_offset);
 }
 
-static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
+static bool gpmi_check_ecc(struct gpmi_nand_data *this)
 {
+	struct nand_chip *chip = &this->nand;
+	struct mtd_info *mtd = nand_to_mtd(&this->nand);
 	struct bch_geometry *geo = &this->bch_geometry;
+	const struct nand_ecc_props *requirements =
+		nanddev_get_ecc_requirements(&chip->base);
+	int corr, ds_corr;
 
 	/* Do the sanity check. */
 	if (GPMI_IS_MXS(this)) {
@@ -248,7 +253,22 @@ static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
 		if (geo->gf_len == 14)
 			return false;
 	}
-	return geo->ecc_strength <= this->devdata->bch_max_ecc_strength;
+
+	if (geo->ecc_strength > this->devdata->bch_max_ecc_strength)
+		return false;
+
+	/* check ecc strength, same as nand_ecc_is_strong_enough() did */
+	if (requirements->step_size) {
+		corr = mtd->writesize * geo->ecc_strength /
+		       geo->ecc_chunk_size;
+		ds_corr = mtd->writesize * requirements->strength /
+			  requirements->step_size;
+		if (corr < ds_corr ||
+		    geo->ecc_strength < requirements->strength)
+			return false;
+	}
+
+	return true;
 }
 
 /*
-- 
2.17.1


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 3/4] mtd: rawnand: gpmi: Rename the variable ecc_chunk_size
  2022-04-04 19:54 [PATCH v3 1/4] mtd: rawnand: gpmi: Refactor bch geometry settings function Han Xu
  2022-04-04 19:54 ` [PATCH v3 2/4] mtd: rawnand: gpmi: Add strict ecc strength check Han Xu
@ 2022-04-04 19:54 ` Han Xu
  2022-04-05  7:29   ` Miquel Raynal
  2022-04-04 19:54 ` [PATCH v3 4/4] mtd: rawnand: gpmi: Add large oob bch setting support Han Xu
  2022-04-05  7:26 ` [PATCH v3 1/4] mtd: rawnand: gpmi: Refactor bch geometry settings function Miquel Raynal
  3 siblings, 1 reply; 9+ messages in thread
From: Han Xu @ 2022-04-04 19:54 UTC (permalink / raw)
  To: sean, frieder.schrempf, festevam
  Cc: ye.li, peng.fan, han.xu, miquel.raynal, linux-mtd

There is only one variable ecc_chunk_size in bch_geometry data
structure but two different field in BCH registers. The data0_size in
BCH_FLASH0LAYOUT0 and datan_size in BCH_FLASH0LAYOUT1 should have
dedicate variable since they might set to different values in some
cases.

Signed-off-by: Han Xu <han.xu@nxp.com>

---
Changes since v2:
 - split the variable rename to a single patch
---
---
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 54 ++++++++++++----------
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h |  9 ++--
 2 files changed, 35 insertions(+), 28 deletions(-)

diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index 9a37f8cc663e..cdbf0e05087f 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -218,7 +218,8 @@ static void gpmi_dump_info(struct gpmi_nand_data *this)
 		"ECC Strength           : %u\n"
 		"Page Size in Bytes     : %u\n"
 		"Metadata Size in Bytes : %u\n"
-		"ECC Chunk Size in Bytes: %u\n"
+		"ECC0 Chunk Size in Bytes: %u\n"
+		"ECCn Chunk Size in Bytes: %u\n"
 		"ECC Chunk Count        : %u\n"
 		"Payload Size in Bytes  : %u\n"
 		"Auxiliary Size in Bytes: %u\n"
@@ -229,7 +230,8 @@ static void gpmi_dump_info(struct gpmi_nand_data *this)
 		geo->ecc_strength,
 		geo->page_size,
 		geo->metadata_size,
-		geo->ecc_chunk_size,
+		geo->ecc0_chunk_size,
+		geo->eccn_chunk_size,
 		geo->ecc_chunk_count,
 		geo->payload_size,
 		geo->auxiliary_size,
@@ -260,7 +262,7 @@ static bool gpmi_check_ecc(struct gpmi_nand_data *this)
 	/* check ecc strength, same as nand_ecc_is_strong_enough() did */
 	if (requirements->step_size) {
 		corr = mtd->writesize * geo->ecc_strength /
-		       geo->ecc_chunk_size;
+		       geo->eccn_chunk_size;
 		ds_corr = mtd->writesize * requirements->strength /
 			  requirements->step_size;
 		if (corr < ds_corr ||
@@ -300,13 +302,14 @@ static int set_geometry_by_ecc_info(struct gpmi_nand_data *this,
 			nanddev_get_ecc_requirements(&chip->base)->step_size);
 		return -EINVAL;
 	}
-	geo->ecc_chunk_size = ecc_step;
+	geo->ecc0_chunk_size = ecc_step;
+	geo->eccn_chunk_size = ecc_step;
 	geo->ecc_strength = round_up(ecc_strength, 2);
 	if (!gpmi_check_ecc(this))
 		return -EINVAL;
 
 	/* Keep the C >= O */
-	if (geo->ecc_chunk_size < mtd->oobsize) {
+	if (geo->eccn_chunk_size < mtd->oobsize) {
 		dev_err(this->dev,
 			"unsupported nand chip. ecc size: %d, oob size : %d\n",
 			ecc_step, mtd->oobsize);
@@ -316,7 +319,7 @@ static int set_geometry_by_ecc_info(struct gpmi_nand_data *this,
 	/* The default value, see comment in the legacy_set_geometry(). */
 	geo->metadata_size = 10;
 
-	geo->ecc_chunk_count = mtd->writesize / geo->ecc_chunk_size;
+	geo->ecc_chunk_count = mtd->writesize / geo->eccn_chunk_size;
 
 	/*
 	 * Now, the NAND chip with 2K page(data chunk is 512byte) shows below:
@@ -438,13 +441,15 @@ static int legacy_set_geometry(struct gpmi_nand_data *this)
 	geo->gf_len = 13;
 
 	/* The default for chunk size. */
-	geo->ecc_chunk_size = 512;
-	while (geo->ecc_chunk_size < mtd->oobsize) {
-		geo->ecc_chunk_size *= 2; /* keep C >= O */
+	geo->ecc0_chunk_size = 512;
+	geo->eccn_chunk_size = 512;
+	while (geo->eccn_chunk_size < mtd->oobsize) {
+		geo->ecc0_chunk_size *= 2; /* keep C >= O */
+		geo->eccn_chunk_size *= 2; /* keep C >= O */
 		geo->gf_len = 14;
 	}
 
-	geo->ecc_chunk_count = mtd->writesize / geo->ecc_chunk_size;
+	geo->ecc_chunk_count = mtd->writesize / geo->eccn_chunk_size;
 
 	/* We use the same ECC strength for all chunks. */
 	geo->ecc_strength = get_ecc_strength(this);
@@ -871,7 +876,7 @@ static int gpmi_raw_len_to_len(struct gpmi_nand_data *this, int raw_len)
 	 * we are passed in exec_op. Calculate the data length from it.
 	 */
 	if (this->bch)
-		return ALIGN_DOWN(raw_len, this->bch_geometry.ecc_chunk_size);
+		return ALIGN_DOWN(raw_len, this->bch_geometry.eccn_chunk_size);
 	else
 		return raw_len;
 }
@@ -1263,7 +1268,7 @@ static int gpmi_count_bitflips(struct nand_chip *chip, void *buf, int first,
 
 			/* Read ECC bytes into our internal raw_buffer */
 			offset = nfc_geo->metadata_size * 8;
-			offset += ((8 * nfc_geo->ecc_chunk_size) + eccbits) * (i + 1);
+			offset += ((8 * nfc_geo->eccn_chunk_size) + eccbits) * (i + 1);
 			offset -= eccbits;
 			bitoffset = offset % 8;
 			eccbytes = DIV_ROUND_UP(offset + eccbits, 8);
@@ -1300,16 +1305,16 @@ static int gpmi_count_bitflips(struct nand_chip *chip, void *buf, int first,
 			if (i == 0) {
 				/* The first block includes metadata */
 				flips = nand_check_erased_ecc_chunk(
-						buf + i * nfc_geo->ecc_chunk_size,
-						nfc_geo->ecc_chunk_size,
+						buf + i * nfc_geo->eccn_chunk_size,
+						nfc_geo->eccn_chunk_size,
 						eccbuf, eccbytes,
 						this->auxiliary_virt,
 						nfc_geo->metadata_size,
 						nfc_geo->ecc_strength);
 			} else {
 				flips = nand_check_erased_ecc_chunk(
-						buf + i * nfc_geo->ecc_chunk_size,
-						nfc_geo->ecc_chunk_size,
+						buf + i * nfc_geo->eccn_chunk_size,
+						nfc_geo->eccn_chunk_size,
 						eccbuf, eccbytes,
 						NULL, 0,
 						nfc_geo->ecc_strength);
@@ -1338,20 +1343,21 @@ static void gpmi_bch_layout_std(struct gpmi_nand_data *this)
 	struct bch_geometry *geo = &this->bch_geometry;
 	unsigned int ecc_strength = geo->ecc_strength >> 1;
 	unsigned int gf_len = geo->gf_len;
-	unsigned int block_size = geo->ecc_chunk_size;
+	unsigned int block0_size = geo->ecc0_chunk_size;
+	unsigned int blockn_size = geo->eccn_chunk_size;
 
 	this->bch_flashlayout0 =
 		BF_BCH_FLASH0LAYOUT0_NBLOCKS(geo->ecc_chunk_count - 1) |
 		BF_BCH_FLASH0LAYOUT0_META_SIZE(geo->metadata_size) |
 		BF_BCH_FLASH0LAYOUT0_ECC0(ecc_strength, this) |
 		BF_BCH_FLASH0LAYOUT0_GF(gf_len, this) |
-		BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(block_size, this);
+		BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(block0_size, this);
 
 	this->bch_flashlayout1 =
 		BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(geo->page_size) |
 		BF_BCH_FLASH0LAYOUT1_ECCN(ecc_strength, this) |
 		BF_BCH_FLASH0LAYOUT1_GF(gf_len, this) |
-		BF_BCH_FLASH0LAYOUT1_DATAN_SIZE(block_size, this);
+		BF_BCH_FLASH0LAYOUT1_DATAN_SIZE(blockn_size, this);
 }
 
 static int gpmi_ecc_read_page(struct nand_chip *chip, uint8_t *buf,
@@ -1451,12 +1457,12 @@ static int gpmi_ecc_read_subpage(struct nand_chip *chip, uint32_t offs,
 		BF_BCH_FLASH0LAYOUT0_META_SIZE(meta) |
 		BF_BCH_FLASH0LAYOUT0_ECC0(ecc_strength, this) |
 		BF_BCH_FLASH0LAYOUT0_GF(geo->gf_len, this) |
-		BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(geo->ecc_chunk_size, this);
+		BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(geo->eccn_chunk_size, this);
 
 	this->bch_flashlayout1 = BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(page_size) |
 		BF_BCH_FLASH0LAYOUT1_ECCN(ecc_strength, this) |
 		BF_BCH_FLASH0LAYOUT1_GF(geo->gf_len, this) |
-		BF_BCH_FLASH0LAYOUT1_DATAN_SIZE(geo->ecc_chunk_size, this);
+		BF_BCH_FLASH0LAYOUT1_DATAN_SIZE(geo->eccn_chunk_size, this);
 
 	this->bch = true;
 
@@ -1625,7 +1631,7 @@ static int gpmi_ecc_read_page_raw(struct nand_chip *chip, uint8_t *buf,
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	struct gpmi_nand_data *this = nand_get_controller_data(chip);
 	struct bch_geometry *nfc_geo = &this->bch_geometry;
-	int eccsize = nfc_geo->ecc_chunk_size;
+	int eccsize = nfc_geo->eccn_chunk_size;
 	int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len;
 	u8 *tmp_buf = this->raw_buffer;
 	size_t src_bit_off;
@@ -1710,7 +1716,7 @@ static int gpmi_ecc_write_page_raw(struct nand_chip *chip, const uint8_t *buf,
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	struct gpmi_nand_data *this = nand_get_controller_data(chip);
 	struct bch_geometry *nfc_geo = &this->bch_geometry;
-	int eccsize = nfc_geo->ecc_chunk_size;
+	int eccsize = nfc_geo->eccn_chunk_size;
 	int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len;
 	u8 *tmp_buf = this->raw_buffer;
 	uint8_t *oob = chip->oob_poi;
@@ -2084,7 +2090,7 @@ static int gpmi_init_last(struct gpmi_nand_data *this)
 	ecc->read_oob_raw = gpmi_ecc_read_oob_raw;
 	ecc->write_oob_raw = gpmi_ecc_write_oob_raw;
 	ecc->engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
-	ecc->size	= bch_geo->ecc_chunk_size;
+	ecc->size	= bch_geo->eccn_chunk_size;
 	ecc->strength	= bch_geo->ecc_strength;
 	mtd_set_ooblayout(mtd, &gpmi_ooblayout_ops);
 
diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
index 5e1c3ddae5f8..5b217feb0ec1 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
@@ -30,9 +30,9 @@ struct resources {
  * @page_size:                The size, in bytes, of a physical page, including
  *                            both data and OOB.
  * @metadata_size:            The size, in bytes, of the metadata.
- * @ecc_chunk_size:           The size, in bytes, of a single ECC chunk. Note
- *                            the first chunk in the page includes both data and
- *                            metadata, so it's a bit larger than this value.
+ * @ecc0_chunk_size:          The size, in bytes, of a first ECC chunk.
+ * @eccn_chunk_size:          The size, in bytes, of a single ECC chunk after
+ *                            the first chunk in the page.
  * @ecc_chunk_count:          The number of ECC chunks in the page,
  * @payload_size:             The size, in bytes, of the payload buffer.
  * @auxiliary_size:           The size, in bytes, of the auxiliary buffer.
@@ -48,7 +48,8 @@ struct bch_geometry {
 	unsigned int  ecc_strength;
 	unsigned int  page_size;
 	unsigned int  metadata_size;
-	unsigned int  ecc_chunk_size;
+	unsigned int  ecc0_chunk_size;
+	unsigned int  eccn_chunk_size;
 	unsigned int  ecc_chunk_count;
 	unsigned int  payload_size;
 	unsigned int  auxiliary_size;
-- 
2.17.1


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 4/4] mtd: rawnand: gpmi: Add large oob bch setting support
  2022-04-04 19:54 [PATCH v3 1/4] mtd: rawnand: gpmi: Refactor bch geometry settings function Han Xu
  2022-04-04 19:54 ` [PATCH v3 2/4] mtd: rawnand: gpmi: Add strict ecc strength check Han Xu
  2022-04-04 19:54 ` [PATCH v3 3/4] mtd: rawnand: gpmi: Rename the variable ecc_chunk_size Han Xu
@ 2022-04-04 19:54 ` Han Xu
  2022-04-05  7:26 ` [PATCH v3 1/4] mtd: rawnand: gpmi: Refactor bch geometry settings function Miquel Raynal
  3 siblings, 0 replies; 9+ messages in thread
From: Han Xu @ 2022-04-04 19:54 UTC (permalink / raw)
  To: sean, frieder.schrempf, festevam
  Cc: ye.li, peng.fan, han.xu, miquel.raynal, linux-mtd

The code change proposes a new way to set bch geometry for large oob
NAND (oobsize > 1KB). In this case, previous implementation can NOT
guarantee the bad block mark always locates in data chunk, so we need a
new way to do it. The general idea is,

1.Try all ECC strength from the maximum ecc that controller can support
  to minimum value required by NAND chip, any ECC strength makes the
  BBM locate in data chunk can be eligible.

2.If none of them works, using separate ECC for meta, which will add
  one extra ecc with the same ECC strength as other data chunks. This
  extra ECC can guarantee BBM located in data chunk, also we need to
  check if oob can afford it.

Signed-off-by: Han Xu <han.xu@nxp.com>

---
 Changes since v2:
 - calculate the ecc strength from max controller can support to minimum
   that NAND chips required.
 - split the variable rename to a single patch

 Changes since v1:
 - split the large oob part to a single patch
---
---
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 199 ++++++++++++++++++++-
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h |   3 +
 2 files changed, 197 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index cdbf0e05087f..bad261e1afd6 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -273,6 +273,39 @@ static bool gpmi_check_ecc(struct gpmi_nand_data *this)
 	return true;
 }
 
+/* check if bbm locates in data chunk rather than ecc chunk */
+static bool bbm_in_data_chunk(struct gpmi_nand_data *this,
+			unsigned int *chunk_num)
+{
+	struct bch_geometry *geo = &this->bch_geometry;
+	struct nand_chip *chip = &this->nand;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	unsigned int i, j;
+
+	if (geo->ecc0_chunk_size != geo->eccn_chunk_size) {
+		dev_err(this->dev,
+			"The size of ecc0_chunk must equal to eccn_chunk\n");
+		return false;
+	}
+
+	i = (mtd->writesize * 8 - geo->metadata_size * 8) /
+		(geo->gf_len * geo->ecc_strength +
+			geo->eccn_chunk_size * 8);
+
+	j = (mtd->writesize * 8 - geo->metadata_size * 8) -
+		(geo->gf_len * geo->ecc_strength +
+			geo->eccn_chunk_size * 8) * i;
+
+	if (j < geo->eccn_chunk_size * 8) {
+		*chunk_num = i+1;
+		dev_dbg(this->dev, "Set ecc to %d and bbm in chunk %d\n",
+				geo->ecc_strength, *chunk_num);
+		return true;
+	}
+
+	return false;
+}
+
 /*
  * If we can get the ECC information from the nand chip, we do not
  * need to calculate them ourselves.
@@ -422,6 +455,134 @@ static inline int get_ecc_strength(struct gpmi_nand_data *this)
 	return round_down(ecc_strength, 2);
 }
 
+static int set_geometry_for_large_oob(struct gpmi_nand_data *this)
+{
+	struct bch_geometry *geo = &this->bch_geometry;
+	struct nand_chip *chip = &this->nand;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_ecc_props *requirements =
+		nanddev_get_ecc_requirements(&chip->base);
+	unsigned int block_mark_bit_offset;
+	unsigned int max_ecc;
+	unsigned int bbm_chunk;
+	unsigned int i;
+
+	/* sanity check for the minimum ecc nand required */
+	if (!(requirements->strength > 0 &&
+	      requirements->step_size > 0))
+		return -EINVAL;
+	geo->ecc_strength = requirements->strength;
+
+	/* check if platform can support this nand */
+	if (!gpmi_check_ecc(this)) {
+		dev_err(this->dev,
+			"unsupported NAND chip, minimum ecc required %d\n",
+			geo->ecc_strength);
+		return -EINVAL;
+	}
+
+	/* calculate the maximum ecc platform can support*/
+	geo->metadata_size = 10;
+	geo->gf_len = 14;
+	geo->ecc0_chunk_size = 1024;
+	geo->eccn_chunk_size = 1024;
+	geo->ecc_chunk_count = mtd->writesize / geo->eccn_chunk_size;
+	max_ecc = min(get_ecc_strength(this),
+		      this->devdata->bch_max_ecc_strength);
+
+	/*
+	 * search a supported ecc strength that makes bbm
+	 * located in data chunk
+	 */
+	geo->ecc_strength = max_ecc;
+	while (!(geo->ecc_strength < requirements->strength)) {
+		if (bbm_in_data_chunk(this, &bbm_chunk))
+			goto geo_setting;
+		geo->ecc_strength -= 2;
+	}
+
+	/* if none of them works, keep using the minimum ecc */
+	/* nand required but changing ecc page layout  */
+	geo->ecc_strength = requirements->strength;
+	/* add extra ecc for meta data */
+	geo->ecc0_chunk_size = 0;
+	geo->ecc_chunk_count = (mtd->writesize / geo->eccn_chunk_size) + 1;
+	geo->ecc_for_meta = 1;
+	/* check if oob can afford this extra ecc chunk */
+	if (mtd->oobsize * 8 < geo->metadata_size * 8 +
+	    geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) {
+		dev_err(this->dev, "unsupported NAND chip with new layout\n");
+		return -EINVAL;
+	}
+
+	/* calculate in which chunk bbm located */
+	bbm_chunk = (mtd->writesize * 8 - geo->metadata_size * 8 -
+		     geo->gf_len * geo->ecc_strength) /
+		     (geo->gf_len * geo->ecc_strength +
+		     geo->eccn_chunk_size * 8) + 1;
+
+geo_setting:
+
+	geo->page_size = mtd->writesize + geo->metadata_size +
+		(geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) / 8;
+	geo->payload_size = mtd->writesize;
+
+	/*
+	 * The auxiliary buffer contains the metadata and the ECC status. The
+	 * metadata is padded to the nearest 32-bit boundary. The ECC status
+	 * contains one byte for every ECC chunk, and is also padded to the
+	 * nearest 32-bit boundary.
+	 */
+	geo->auxiliary_status_offset = ALIGN(geo->metadata_size, 4);
+	geo->auxiliary_size = ALIGN(geo->metadata_size, 4)
+				    + ALIGN(geo->ecc_chunk_count, 4);
+
+	if (!this->swap_block_mark)
+		return 0;
+
+	/* calculate the number of ecc chunk behind the bbm */
+	i = (mtd->writesize / geo->eccn_chunk_size) - bbm_chunk + 1;
+
+	block_mark_bit_offset = mtd->writesize * 8 -
+		(geo->ecc_strength * geo->gf_len * (geo->ecc_chunk_count - i)
+		+ geo->metadata_size * 8);
+
+	geo->block_mark_byte_offset = block_mark_bit_offset / 8;
+	geo->block_mark_bit_offset  = block_mark_bit_offset % 8;
+
+	dev_dbg(this->dev, "BCH Geometry :\n"
+		"GF length              : %u\n"
+		"ECC Strength           : %u\n"
+		"Page Size in Bytes     : %u\n"
+		"Metadata Size in Bytes : %u\n"
+		"ECC0 Chunk Size in Bytes: %u\n"
+		"ECCn Chunk Size in Bytes: %u\n"
+		"ECC Chunk Count        : %u\n"
+		"Payload Size in Bytes  : %u\n"
+		"Auxiliary Size in Bytes: %u\n"
+		"Auxiliary Status Offset: %u\n"
+		"Block Mark Byte Offset : %u\n"
+		"Block Mark Bit Offset  : %u\n"
+		"Block Mark in chunk	: %u\n"
+		"Ecc for Meta data	: %u\n",
+		geo->gf_len,
+		geo->ecc_strength,
+		geo->page_size,
+		geo->metadata_size,
+		geo->ecc0_chunk_size,
+		geo->eccn_chunk_size,
+		geo->ecc_chunk_count,
+		geo->payload_size,
+		geo->auxiliary_size,
+		geo->auxiliary_status_offset,
+		geo->block_mark_byte_offset,
+		geo->block_mark_bit_offset,
+		bbm_chunk,
+		geo->ecc_for_meta);
+
+	return 0;
+}
+
 static int legacy_set_geometry(struct gpmi_nand_data *this)
 {
 	struct bch_geometry *geo = &this->bch_geometry;
@@ -557,6 +718,14 @@ static int common_nfc_set_geometry(struct gpmi_nand_data *this)
 			return 0;
 	}
 
+	/* for large oob nand */
+	if (mtd->oobsize > 1024) {
+		dev_dbg(this->dev, "use large oob bch geometry\n");
+		err = set_geometry_for_large_oob(this);
+		if (!err)
+			return 0;
+	}
+
 	/* otherwise use the minimum ecc nand chip required */
 	dev_dbg(this->dev, "use minimum ecc bch geometry\n");
 	err = set_geometry_by_ecc_info(this, requirements->strength,
@@ -1440,24 +1609,44 @@ static int gpmi_ecc_read_subpage(struct nand_chip *chip, uint32_t offs,
 		}
 	}
 
+	/*
+	 * if there is an ECC dedicate for meta:
+	 * - need to add an extra ECC size when calculating col and page_size,
+	 *   if the meta size is NOT zero.
+	 * - ecc0_chunk size need to set to the same size as other chunks,
+	 *   if the meta size is zero.
+	 */
+
 	meta = geo->metadata_size;
 	if (first) {
-		col = meta + (size + ecc_parity_size) * first;
+		if (geo->ecc_for_meta)
+			col = meta + ecc_parity_size
+				+ (size + ecc_parity_size) * first;
+		else
+			col = meta + (size + ecc_parity_size) * first;
+
 		meta = 0;
 		buf = buf + first * size;
 	}
 
 	ecc_parity_size = geo->gf_len * geo->ecc_strength / 8;
-
 	n = last - first + 1;
-	page_size = meta + (size + ecc_parity_size) * n;
+
+	if (geo->ecc_for_meta && meta)
+		page_size = meta + ecc_parity_size
+			    + (size + ecc_parity_size) * n;
+	else
+		page_size = meta + (size + ecc_parity_size) * n;
+
 	ecc_strength = geo->ecc_strength >> 1;
 
-	this->bch_flashlayout0 = BF_BCH_FLASH0LAYOUT0_NBLOCKS(n - 1) |
+	this->bch_flashlayout0 = BF_BCH_FLASH0LAYOUT0_NBLOCKS(
+		(geo->ecc_for_meta ? n : n - 1)) |
 		BF_BCH_FLASH0LAYOUT0_META_SIZE(meta) |
 		BF_BCH_FLASH0LAYOUT0_ECC0(ecc_strength, this) |
 		BF_BCH_FLASH0LAYOUT0_GF(geo->gf_len, this) |
-		BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(geo->eccn_chunk_size, this);
+		BF_BCH_FLASH0LAYOUT0_DATA0_SIZE((geo->ecc_for_meta ?
+		0 : geo->ecc0_chunk_size), this);
 
 	this->bch_flashlayout1 = BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(page_size) |
 		BF_BCH_FLASH0LAYOUT1_ECCN(ecc_strength, this) |
diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
index 5b217feb0ec1..c3ff56ac62a7 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
@@ -42,6 +42,8 @@ struct resources {
  *                            which the underlying physical block mark appears.
  * @block_mark_bit_offset:    The bit offset into the ECC-based page view at
  *                            which the underlying physical block mark appears.
+ * @ecc_for_meta:             The flag to indicate if there is a dedicate ecc
+ *                            for meta.
  */
 struct bch_geometry {
 	unsigned int  gf_len;
@@ -56,6 +58,7 @@ struct bch_geometry {
 	unsigned int  auxiliary_status_offset;
 	unsigned int  block_mark_byte_offset;
 	unsigned int  block_mark_bit_offset;
+	unsigned int  ecc_for_meta; /* ECC for meta data */
 };
 
 /**
-- 
2.17.1


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^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 1/4] mtd: rawnand: gpmi: Refactor bch geometry settings function
  2022-04-04 19:54 [PATCH v3 1/4] mtd: rawnand: gpmi: Refactor bch geometry settings function Han Xu
                   ` (2 preceding siblings ...)
  2022-04-04 19:54 ` [PATCH v3 4/4] mtd: rawnand: gpmi: Add large oob bch setting support Han Xu
@ 2022-04-05  7:26 ` Miquel Raynal
  3 siblings, 0 replies; 9+ messages in thread
From: Miquel Raynal @ 2022-04-05  7:26 UTC (permalink / raw)
  To: Han Xu; +Cc: sean, frieder.schrempf, festevam, ye.li, peng.fan, linux-mtd

Hi Han,

han.xu@nxp.com wrote on Mon,  4 Apr 2022 14:54:24 -0500:

> The code change refactor the bch geometry setting function, which still
> use the legacy bch setting as default option, while user may choose to
> use chips required minimum ecc strength by DT flag "fsl,use-minimum-ecc".
> 
> The driver uses legacy bch geometry settings by default, if the NAND

Shall we really refer to a legacy geometry? It's just that there was a
default value until know, you need another default for bigger devices,
but the ancient geometry is still completely valid (at least for
existing devices).

Can you change the naming? You can however mention in a comment
that this way of deriving the geometry is deprecated for larger devices
(and mention the split).

Otherwise LGTM.

> chips oob size is less than 1KB. The legacy_set_geometry() sets the data
> chunk size(step_size) larger than oob size to make sure BBM locates in
> data chunk, then set the maximum ecc strength oob can hold. It always use
> unbalanced ECC layout, which ecc0 will cover both meta and data0 chunk.
> 
> For all other cases,set the bch geometry by chip required strength and
> step size, which uses the minimum ecc strength chip required. It can be
> explicitly enabled by DT flag "fsl,use-minimum-ecc", but need to be
> en/disabled in both u-boot and kernel at the same time.
> 
> Signed-off-by: Han Xu <han.xu@nxp.com>
> Tested-by: Sean Nyekjaer <sean@geanix.com>
> 
> ---
> Changes since v2
>  - split the ecc check to a single patch
> 
> Changes since v1
>  - split the patch to two parts
>  - change the commit log
>  - add test tag
> ---
> ---
>  drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 32 ++++++++++++++--------
>  1 file changed, 20 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> index d96899fa90b7..4144d5937103 100644
> --- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> +++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> @@ -514,24 +514,32 @@ static int legacy_set_geometry(struct gpmi_nand_data *this)
>  static int common_nfc_set_geometry(struct gpmi_nand_data *this)
>  {
>  	struct nand_chip *chip = &this->nand;
> +	struct mtd_info *mtd = nand_to_mtd(&this->nand);
>  	const struct nand_ecc_props *requirements =
>  		nanddev_get_ecc_requirements(&chip->base);
> +	bool use_minimun_ecc;
> +	int err;
>  
> -	if (chip->ecc.strength > 0 && chip->ecc.size > 0)
> -		return set_geometry_by_ecc_info(this, chip->ecc.strength,
> -						chip->ecc.size);
> -
> -	if ((of_property_read_bool(this->dev->of_node, "fsl,use-minimum-ecc"))
> -				|| legacy_set_geometry(this)) {
> -		if (!(requirements->strength > 0 && requirements->step_size > 0))
> -			return -EINVAL;
> +	use_minimun_ecc = of_property_read_bool(this->dev->of_node,
> +						"fsl,use-minimum-ecc");
>  
> -		return set_geometry_by_ecc_info(this,
> -						requirements->strength,
> -						requirements->step_size);
> +	/* use legacy bch geometry settings by default*/
> +	if ((!use_minimun_ecc && mtd->oobsize < 1024) ||
> +	    !(requirements->strength > 0 && requirements->step_size > 0)) {
> +		dev_dbg(this->dev, "use legacy bch geometry\n");
> +		err = legacy_set_geometry(this);
> +		if (!err)
> +			return 0;
>  	}
>  
> -	return 0;
> +	/* otherwise use the minimum ecc nand chip required */
> +	dev_dbg(this->dev, "use minimum ecc bch geometry\n");
> +	err = set_geometry_by_ecc_info(this, requirements->strength,
> +					requirements->step_size);
> +	if (err)
> +		dev_err(this->dev, "none of the bch geometry setting works\n");
> +
> +	return err;
>  }
>  
>  /* Configures the geometry for BCH.  */


Thanks,
Miquèl

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^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 2/4] mtd: rawnand: gpmi: Add strict ecc strength check
  2022-04-04 19:54 ` [PATCH v3 2/4] mtd: rawnand: gpmi: Add strict ecc strength check Han Xu
@ 2022-04-05  7:28   ` Miquel Raynal
  2022-04-08 22:05     ` Han Xu
  0 siblings, 1 reply; 9+ messages in thread
From: Miquel Raynal @ 2022-04-05  7:28 UTC (permalink / raw)
  To: Han Xu; +Cc: sean, frieder.schrempf, festevam, ye.li, peng.fan, linux-mtd

Hi Han,

han.xu@nxp.com wrote on Mon,  4 Apr 2022 14:54:25 -0500:

> Add strict ecc strength check in gpmi_check_ecc() function, which is
> same as nand_ecc_is_strong_enough() did. It will check both correct bits
> and correct bits per byte to ensure it meets chip required ecc strength.
> 
> Signed-off-by: Han Xu <han.xu@nxp.com>
> 
> ---
> Changes since v2:
>  - split the ecc check to a single patch
> ---
> ---
>  drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 24 ++++++++++++++++++++--
>  1 file changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> index 4144d5937103..9a37f8cc663e 100644
> --- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> +++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> @@ -238,9 +238,14 @@ static void gpmi_dump_info(struct gpmi_nand_data *this)
>  		geo->block_mark_bit_offset);
>  }
>  
> -static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
> +static bool gpmi_check_ecc(struct gpmi_nand_data *this)

This change should be in a separate commit.

>  {
> +	struct nand_chip *chip = &this->nand;
> +	struct mtd_info *mtd = nand_to_mtd(&this->nand);
>  	struct bch_geometry *geo = &this->bch_geometry;
> +	const struct nand_ecc_props *requirements =
> +		nanddev_get_ecc_requirements(&chip->base);
> +	int corr, ds_corr;
>  
>  	/* Do the sanity check. */
>  	if (GPMI_IS_MXS(this)) {
> @@ -248,7 +253,22 @@ static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
>  		if (geo->gf_len == 14)
>  			return false;
>  	}
> -	return geo->ecc_strength <= this->devdata->bch_max_ecc_strength;
> +
> +	if (geo->ecc_strength > this->devdata->bch_max_ecc_strength)
> +		return false;
> +
> +	/* check ecc strength, same as nand_ecc_is_strong_enough() did */

Why not using nand_ecc_is_strong_enough() in this case?

> +	if (requirements->step_size) {
> +		corr = mtd->writesize * geo->ecc_strength /
> +		       geo->ecc_chunk_size;
> +		ds_corr = mtd->writesize * requirements->strength /
> +			  requirements->step_size;
> +		if (corr < ds_corr ||
> +		    geo->ecc_strength < requirements->strength)
> +			return false;
> +	}
> +
> +	return true;
>  }
>  
>  /*


Thanks,
Miquèl

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http://lists.infradead.org/mailman/listinfo/linux-mtd/

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 3/4] mtd: rawnand: gpmi: Rename the variable ecc_chunk_size
  2022-04-04 19:54 ` [PATCH v3 3/4] mtd: rawnand: gpmi: Rename the variable ecc_chunk_size Han Xu
@ 2022-04-05  7:29   ` Miquel Raynal
  0 siblings, 0 replies; 9+ messages in thread
From: Miquel Raynal @ 2022-04-05  7:29 UTC (permalink / raw)
  To: Han Xu; +Cc: sean, frieder.schrempf, festevam, ye.li, peng.fan, linux-mtd

Hi Han,

han.xu@nxp.com wrote on Mon,  4 Apr 2022 14:54:26 -0500:

> There is only one variable ecc_chunk_size in bch_geometry data
> structure but two different field in BCH registers. The data0_size in
> BCH_FLASH0LAYOUT0 and datan_size in BCH_FLASH0LAYOUT1 should have
> dedicate variable since they might set to different values in some
> cases.

Great, thanks.

I assume this patch brings no functional change and should not be
expected to bring any regression. If so, can you please state it in the
commit log?

> 
> Signed-off-by: Han Xu <han.xu@nxp.com>
> 

Thanks,
Miquèl

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 2/4] mtd: rawnand: gpmi: Add strict ecc strength check
  2022-04-05  7:28   ` Miquel Raynal
@ 2022-04-08 22:05     ` Han Xu
  2022-04-11  7:30       ` Miquel Raynal
  0 siblings, 1 reply; 9+ messages in thread
From: Han Xu @ 2022-04-08 22:05 UTC (permalink / raw)
  To: Miquel Raynal
  Cc: sean, frieder.schrempf, festevam, ye.li, peng.fan, linux-mtd

On 22/04/05 09:28AM, Miquel Raynal wrote:
> Hi Han,
> 
> han.xu@nxp.com wrote on Mon,  4 Apr 2022 14:54:25 -0500:
> 
> > Add strict ecc strength check in gpmi_check_ecc() function, which is
> > same as nand_ecc_is_strong_enough() did. It will check both correct bits
> > and correct bits per byte to ensure it meets chip required ecc strength.
> > 
> > Signed-off-by: Han Xu <han.xu@nxp.com>
> > 
> > ---
> > Changes since v2:
> >  - split the ecc check to a single patch
> > ---
> > ---
> >  drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 24 ++++++++++++++++++++--
> >  1 file changed, 22 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> > index 4144d5937103..9a37f8cc663e 100644
> > --- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> > +++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> > @@ -238,9 +238,14 @@ static void gpmi_dump_info(struct gpmi_nand_data *this)
> >  		geo->block_mark_bit_offset);
> >  }
> >  
> > -static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
> > +static bool gpmi_check_ecc(struct gpmi_nand_data *this)
> 
> This change should be in a separate commit.
> 
> >  {
> > +	struct nand_chip *chip = &this->nand;
> > +	struct mtd_info *mtd = nand_to_mtd(&this->nand);
> >  	struct bch_geometry *geo = &this->bch_geometry;
> > +	const struct nand_ecc_props *requirements =
> > +		nanddev_get_ecc_requirements(&chip->base);
> > +	int corr, ds_corr;
> >  
> >  	/* Do the sanity check. */
> >  	if (GPMI_IS_MXS(this)) {
> > @@ -248,7 +253,22 @@ static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
> >  		if (geo->gf_len == 14)
> >  			return false;
> >  	}
> > -	return geo->ecc_strength <= this->devdata->bch_max_ecc_strength;
> > +
> > +	if (geo->ecc_strength > this->devdata->bch_max_ecc_strength)
> > +		return false;
> > +
> > +	/* check ecc strength, same as nand_ecc_is_strong_enough() did */
> 
> Why not using nand_ecc_is_strong_enough() in this case?

Hi Miquèl,

1. current nand_ecc_is_strong_enough() compared required ecc with conf ecc, but
I only see conf was initialized in some spi-nand and sw ecc drivers. Not sure if
it's a issue or someting missed in the gpmi driver? On my side,
nand_ecc_is_strong_enough() just returned.

2. I remembered that nand_ecc_is_strong_enough() used to compare required ecc
with nand_ecc_ctrl ecc strength, but even in this case, I don't know if it's a
good idea just directly call this function. Usually the driver looking for a
proper bch setting and get the ecc strength/step, at last set the nand_ecc_ctrl
. So at this moment, it's not ready to use nand_ecc_is_strong_enough().

> 
> > +	if (requirements->step_size) {
> > +		corr = mtd->writesize * geo->ecc_strength /
> > +		       geo->ecc_chunk_size;
> > +		ds_corr = mtd->writesize * requirements->strength /
> > +			  requirements->step_size;
> > +		if (corr < ds_corr ||
> > +		    geo->ecc_strength < requirements->strength)
> > +			return false;
> > +	}
> > +
> > +	return true;
> >  }
> >  
> >  /*
> 
> 
> Thanks,
> Miquèl

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^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 2/4] mtd: rawnand: gpmi: Add strict ecc strength check
  2022-04-08 22:05     ` Han Xu
@ 2022-04-11  7:30       ` Miquel Raynal
  0 siblings, 0 replies; 9+ messages in thread
From: Miquel Raynal @ 2022-04-11  7:30 UTC (permalink / raw)
  To: Han Xu; +Cc: sean, frieder.schrempf, festevam, ye.li, peng.fan, linux-mtd

Hi Han,

han.xu@nxp.com wrote on Fri, 8 Apr 2022 17:05:41 -0500:

> On 22/04/05 09:28AM, Miquel Raynal wrote:
> > Hi Han,
> > 
> > han.xu@nxp.com wrote on Mon,  4 Apr 2022 14:54:25 -0500:
> >   
> > > Add strict ecc strength check in gpmi_check_ecc() function, which is
> > > same as nand_ecc_is_strong_enough() did. It will check both correct bits
> > > and correct bits per byte to ensure it meets chip required ecc strength.
> > > 
> > > Signed-off-by: Han Xu <han.xu@nxp.com>
> > > 
> > > ---
> > > Changes since v2:
> > >  - split the ecc check to a single patch
> > > ---
> > > ---
> > >  drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 24 ++++++++++++++++++++--
> > >  1 file changed, 22 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> > > index 4144d5937103..9a37f8cc663e 100644
> > > --- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> > > +++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
> > > @@ -238,9 +238,14 @@ static void gpmi_dump_info(struct gpmi_nand_data *this)
> > >  		geo->block_mark_bit_offset);
> > >  }
> > >  
> > > -static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
> > > +static bool gpmi_check_ecc(struct gpmi_nand_data *this)  
> > 
> > This change should be in a separate commit.
> >   
> > >  {
> > > +	struct nand_chip *chip = &this->nand;
> > > +	struct mtd_info *mtd = nand_to_mtd(&this->nand);
> > >  	struct bch_geometry *geo = &this->bch_geometry;
> > > +	const struct nand_ecc_props *requirements =
> > > +		nanddev_get_ecc_requirements(&chip->base);
> > > +	int corr, ds_corr;
> > >  
> > >  	/* Do the sanity check. */
> > >  	if (GPMI_IS_MXS(this)) {
> > > @@ -248,7 +253,22 @@ static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
> > >  		if (geo->gf_len == 14)
> > >  			return false;
> > >  	}
> > > -	return geo->ecc_strength <= this->devdata->bch_max_ecc_strength;
> > > +
> > > +	if (geo->ecc_strength > this->devdata->bch_max_ecc_strength)
> > > +		return false;
> > > +
> > > +	/* check ecc strength, same as nand_ecc_is_strong_enough() did */  
> > 
> > Why not using nand_ecc_is_strong_enough() in this case?  
> 
> Hi Miquèl,
> 
> 1. current nand_ecc_is_strong_enough() compared required ecc with conf ecc, but
> I only see conf was initialized in some spi-nand and sw ecc drivers. Not sure if
> it's a issue or someting missed in the gpmi driver? On my side,
> nand_ecc_is_strong_enough() just returned.

It was indeed meant to be used primarily by the new ECC engine
abstraction, but it's best not to duplicate this logic over and over
again, so if filling a nand_ecc_props structure is all it takes to be
able to use this helper, it's probably worth trying?

> 2. I remembered that nand_ecc_is_strong_enough() used to compare required ecc
> with nand_ecc_ctrl ecc strength, but even in this case, I don't know if it's a
> good idea just directly call this function. Usually the driver looking for a
> proper bch setting and get the ecc strength/step, at last set the nand_ecc_ctrl
> . So at this moment, it's not ready to use nand_ecc_is_strong_enough().
> >   
> > > +	if (requirements->step_size) {
> > > +		corr = mtd->writesize * geo->ecc_strength /
> > > +		       geo->ecc_chunk_size;
> > > +		ds_corr = mtd->writesize * requirements->strength /
> > > +			  requirements->step_size;
> > > +		if (corr < ds_corr ||
> > > +		    geo->ecc_strength < requirements->strength)
> > > +			return false;
> > > +	}
> > > +
> > > +	return true;
> > >  }
> > >  
> > >  /*  
> > 
> > 
> > Thanks,
> > Miquèl  


Thanks,
Miquèl

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Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2022-04-11  7:32 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-04-04 19:54 [PATCH v3 1/4] mtd: rawnand: gpmi: Refactor bch geometry settings function Han Xu
2022-04-04 19:54 ` [PATCH v3 2/4] mtd: rawnand: gpmi: Add strict ecc strength check Han Xu
2022-04-05  7:28   ` Miquel Raynal
2022-04-08 22:05     ` Han Xu
2022-04-11  7:30       ` Miquel Raynal
2022-04-04 19:54 ` [PATCH v3 3/4] mtd: rawnand: gpmi: Rename the variable ecc_chunk_size Han Xu
2022-04-05  7:29   ` Miquel Raynal
2022-04-04 19:54 ` [PATCH v3 4/4] mtd: rawnand: gpmi: Add large oob bch setting support Han Xu
2022-04-05  7:26 ` [PATCH v3 1/4] mtd: rawnand: gpmi: Refactor bch geometry settings function Miquel Raynal

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